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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
cc: pgsql-hackers@lists.postgresql.org, Noah Misch <noah@leadboat.com>,
        Peter Geoghegan <pg@bowt.ie>, David Rowley <dgrowleyml@gmail.com>
Subject: Re: Intermittent buildfarm failures on wrasse
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Comments: In-reply-to Andres Freund <andres@anarazel.de>
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Andres Freund <andres@anarazel.de> writes:
> On April 15, 2022 2:14:47 PM EDT, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I could use some help filling in the XXX comments, because it's far
>> from clear to me *why* walsenders need this to happen.

> If you want to  commit before: The reason is that walsenders use their x=
min to represent the xmin of standbys when using hot_standby_feedback. Sin=
ce we're only transmitting global horizons up from standbys, it has to inf=
luence globally (and it would be hard to represent per db horizons anyway)=
.

Got it.  I rewrote the comments and pushed.  Noah, it should be safe
to turn wrasse back on.

			regards, tom lane